1. Field of the Invention
The present invention relates to a steering device and in particular to a steering device for a wheel loader in which a front frame and a rear frame are pivotably coupled in the horizontal direction.
2. Background Information
A wheel loader is provided with a handle for performing a steering operation when traveling at a high speed on a public road or at a work site. A lever such as a joystick is also provided to allow for effective steering with simple operations at a work site where steering operations for short distances are repeated.
There is a possibility that an unintentional steering operation may be performed when the driver mistakenly touches the lever while operating the handle on a wheel loader in which both handle and lever operations may be used for steering as described above.
Accordingly, a control device for a material handling machine described in Japanese Laid-open Patent Publication No. 2005-535487 is configured so that a handle operation is prioritized when the handle and the lever are operated at the same time. Specifically, the device described in Japanese Laid-open Patent Publication No. 2005-535487 is provided with a sequence valve along with a control valve for a lever operation. When the handle is operated, the sequence valve is actuated by operating fluid fed by a control valve for the handle operation, and the supply of the operating fluid from the control valve for the lever operation to a steering cylinder is blocked.